feat(nex-be): 添加 UDP服务器功能

- 实现了一个监听

nex-be/src/main/java/com/unisinsight/project/udp/UDPServer.java

@@ -0,0 +1,93 @@
+package com.unisinsight.project.udp;
+
+import cn.hutool.extra.spring.SpringUtil;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import javax.annotation.PostConstruct;
+import javax.annotation.PreDestroy;
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.SocketException;
+import java.net.UnknownHostException;
+
+@Component
+public class UDPServer {
+    
+    private static final Logger logger = LoggerFactory.getLogger(UDPServer.class);
+    
+    private static final int PORT = 8115;
+    
+    private DatagramSocket socket;
+    private Thread serverThread;
+    private volatile boolean running = false;
+    
+    @PostConstruct
+    public void start() {
+        try {
+            socket = new DatagramSocket(PORT);
+            running = true;
+            
+            serverThread = new Thread(() -> {
+                byte[] buffer = new byte[1024];
+                
+                while (running) {
+                    try {
+                        DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
+                        socket.receive(packet);
+                        
+                        // 处理接收到的数据
+                        handlePacket(packet);
+                    } catch (IOException e) {
+                        if (running) {
+                            logger.error("UDP服务器接收数据时发生错误", e);
+                        }
+                    }
+                }
+            });
+            
+            serverThread.start();
+            logger.info("UDP服务器已启动，监听端口: {}", PORT);
+        } catch (SocketException e) {
+            logger.error("UDP服务器启动失败，端口: {}", PORT, e);
+        }
+    }
+    
+    private void handlePacket(DatagramPacket packet) {
+        try {
+            // 获取客户端地址和端口
+            InetAddress clientAddress = packet.getAddress();
+            int clientPort = packet.getPort();
+            
+            // 获取主机IP地址
+            String hostIP = InetAddress.getLocalHost().getHostAddress();
+            String serverPort = SpringUtil.getProperty("server.port");
+            // 将主机IP地址发送回客户端
+            byte[] responseData = hostIP.getBytes();
+            DatagramPacket responsePacket = new DatagramPacket(responseData, responseData.length, clientAddress, clientPort);
+            socket.send(responsePacket);
+
+
+            logger.info("已向客户端 {}/{} 返回主机IP地址: {}:{}", clientAddress.getHostAddress(), clientPort, hostIP, serverPort);
+        } catch (UnknownHostException e) {
+            logger.error("无法获取本机IP地址", e);
+        } catch (IOException e) {
+            logger.error("向客户端发送数据时发生错误", e);
+        }
+    }
+    
+    @PreDestroy
+    public void stop() {
+        running = false;
+        if (socket != null && !socket.isClosed()) {
+            socket.close();
+        }
+        if (serverThread != null) {
+            serverThread.interrupt();
+        }
+        logger.info("UDP服务器已停止");
+    }
+}